The investigators plan to invite all children in the UK with biliary atresia, treated at the three national centres (Birmingham, Kings College and Leeds), over a three year period to take part in a randomised control study. The investigators aim to determine the effectiveness of CoSeal® Surgical Sealant (an anti-adhesive agent) in reducing intra-abdominal adhesions (scar tissue) and the morbidity caused by these adhesions in children treated with a Kasai hepatoportoenterostomy. Adhesions are common, if not invariable, after any abdominal surgery. They cause intra-abdominal organs to become stuck to each other and the abdominal wall. This means they are no longer completely free to slide over each other. In particular patients have a lifetime risk that the bowel can become kinked or twisted leading to complications such as bowel obstruction. Adhesions also make repeat abdominal operations more difficult. The adhesions have to be divided in order to separate the organs from each other and the abdominal wall. This can lead to blood loss and increases the risk of damage to these organs. Anti-adhesive agents have been created to reduce the severity of these adhesions, but there is little in the medical literature to evaluate their effectiveness, particularly in children. Biliary atresia is an obliterative obstruction of the bile ducts that occurs in infants. Initially they are treated by an abdominal operation called a Kasai portoenterostomy to restore bile flow from the liver to the intestines. However approximately 40% of these children will go on to require a liver transplant operation in the first two years of life. If CoSeal® Surgical Sealant is effective this could reduce the patients lifetime risk of complications from abdominal adhesions and also facilitate repeat abdominal operations for these children, in particular for those who go on to require a liver transplant.